1. Field of the Invention
The invention relates to an antitheft system for an automotive vehicle. More particularly, the invention relates to such a system connected to the electrical system of a conventional vehicle thereby preventing the vehicle engine from running without the User first turning a key switch to a run position and then activating a momentary switch. In this manner, an unauthorized user of the vehicle will be unable to start the vehicle engine.
2. Description of the Prior Art
Vehicles have been provided with antitheft systems and with alarm systems. However, the majority of vehicle thefts occur when the ignition key is inadvertently left in an unoccupied vehicle, when the vehicle is push started, or when the vehicle is "hot wired". A system to prevent unauthorized use of the vehicle under these circumstances would, therefore, prevent a majority of vehicle thefts.
Murphy, U.S. Pat. No. 5,061,915, entitled ANTI-THEFT DEVICE FOR MOTORIZED VEHICLES, discloses a device wherein an alarm is energized and the vehicle starter is disabled when there is an attempt to start the vehicle without following a prescribed sequence of disarming steps. However, the Murphy device can be bypassed at the vehicle starter by an unauthorized user because the device only disarms the starter and not the engine itself. In addition, the Murphy device continually draws power from the vehicle battery while in the valet mode so that if battery power is lost for any reason, the alarm will sound when the power is restored.
Baxter, U.S. Pat. No. 4,301,441, entitled ALARM AND ANTITHEFT SYSTEM FOR AN AUTOMOTIVE VEHICLE, discloses an alarm and antitheft system which disables the starter of the vehicle. The Baxter system has the same drawbacks of the Murphy system. In addition, the Baxter system includes numerous relays and switches which results in a high manufacturing cost and installation of the system.